\begin{tikzpicture}[scale=.9] % 复杂
    \pgfmathsetmacro{\a}{0.6}

    % 绘制“正方形的渐开线”
    \tkzDefPoints{0/0/p0, -\a/0/p1, -\a/\a/p2, 0/\a/p3}
    \foreach \i in {4,5, ..., 8} {
        \pgfmathsetmacro{\o}{int(mod(\i, 4))}
        \pgfmathsetmacro{\s}{int(\i - 1)}
        \tkzDefPointBy[rotation=center {p\o} angle -90]({p\s})  \tkzGetPoint{{p\i}}
        \tkzDrawArc({p\o},{p\i})({p\s})
    }
    % 绘制最后的一小节
    \tkzDefPointBy[rotation=center p0 angle -50](p8)  \tkzGetPoint{X}
    \tkzDrawArc({p0},X)(p8)

    % 绘制正方形及其延长线
    \tkzDrawLine[add=0 and 0.2](p0, p7)
    \tkzDrawLine[add=0 and 0.2](p1, p8)
    \tkzDrawLine[add=0 and 0.2](p2, p5)
    \tkzDrawLine[add=0 and 0.2](p3, p6)

    % 显示坐标点
    \tkzLabelPoint[below](p0){$A$}
    \tkzLabelPoint[left](p1){$B$}
    \tkzLabelPoint[above](p2){$C$}
    \tkzLabelPoint[above right](p3){$D$}
    \tkzLabelPoint[below right](p4){$E$}
    \tkzLabelPoint[below right](p5){$F$}
    \tkzLabelPoint[below left](p6){$G$}
    \tkzLabelPoint[above right](p7){$H$}
    \tkzLabelPoint[below right](p8){$K$}
\end{tikzpicture}

